The invention relates to the technical sector of female contraceptive means and methods.
Various methods of female contraception are known using oestroprogestative pills, progestin-only pills, hormonal intrauterine devices (IUD), copper IUDs, etc., and all these means and methods have well-known benefits and side effects. The use of male or female condoms is also common, as is pre-ejaculatory withdrawal, or certain natural methods (called symptom-based methods), the rhythm method or the cervical mucous method (Billings ovulation method). Sterilisation for contraceptive purposes is also performed, requiring the patient's free choice after consultation with a physician; some of these methods are performed abdominally and require general anaesthesia (either by laparotomy, laparoscopy or posterior vaginal culdotomy). Other methods have been tested hysteroscopically (uterine endoscopy) with the insertion of a cone plug, polyethylene plugs with spicules, or hydrogel-based plugs.
Currently, the reference method is the “Essure” device, which produces an inflammatory reaction. There is a risk that insertion may fail, while another disadvantage is that the technique is irreversible. It is an alternative to surgical sterilisation and consists in the selective occlusion of the Fallopian tube by inserting a micro-coil approximately 4 cm in length into each of the patient's Fallopian tubes. This micro-coil contains polyethylene terephthalate fibres that elicit a natural tissue reaction, which leads to occlusion.
From the prior art, we know of the reversible female sterilisation devices described in patents EP 0010812 and U.S. 2009/056722, which make it possible to obtain opposite forms on either side of a median tubal part that can be anchored into the Fallopian tube and its opening. More particularly, in the aforementioned US patent, the device has wing shapes with a conical configuration for anchoring in the aforementioned Fallopian tube. These devices are not, however, suited to the control of cell tissue deterioration inside the Fallopian tube.
We also know from U.S. Pat. No. 5,979,446 that there is a contraceptive device with flexible fingerlike protrusions around the sides and which is attached by anchoring it into the tubal mucosa, providing no protection and allowing spermatozoa to pass through.
The applicants have sought to remedy these drawbacks.
Their approach led to the need for a detailed examination of the Fallopian tube and a definition of its constituent characteristics. FIG. 1 is therefore provided to help to understand the invention, with the anatomy of the Fallopian tube comprising four successive parts starting from the uterus, i.e. a uterine or interstitial part (a), the median part (b) called the isthmic portion, the part comprising the ampulla/infundibulum (c), and the abdominal ostium. The first two parts, which are of interest for the invention, are 1 to 1.5 cm and 3 to 4 cm long, respectively. For the uterine or interstitial part, the ostial diameter is approximately 1 mm and the internal diameter, or lumen, is 0.2 to 0.5 mm. The diameter of an oocyte is 0.1 mm. For the isthmic portion, the lumen is 2 to 4 mm; it is cylindrical and its muscular wall is thick, hard and not very extensible.
Additionally, FIGS. 2, 2a, 2b and 2c represent the anatomy of the Fallopian tube to help to understand the invention. Sections A, B and C show the different sections corresponding to different areas of the Fallopian tube and present its internal structure. The number 1 indicates the peritoneum, 2 the subserosa, 3 the plexiform molecular layer, 4 the annular molecular layer, 5 the vessels, 6 the migration channel for ova and spermatozoa. Number 7 represents the alveoli formed randomly between the haustrations or mucous folds (8) inside the Fallopian tube.
In view of the aforementioned known prior art, and of the composition of the Fallopian tube, the Applicants' approach was to study a new design for female contraception that is natural, reversible and without undesirable side effects, and limiting cell destruction when removing the sterilisation device.
Given the problems posed, this analysis thus made it possible to develop a new, original solution for a new contraceptive method that is easy to implement while avoiding all inflammatory reactions and is reversible, in other words the initial situation can be returned to without any damage for the patient who desires another pregnancy.